An apparatus according to the above is for example known from U.S. Pat. No. 6,105,419. In this patent an apparatus for inspecting sealed packages is disclosed, wherein first inspection means contacts the packages to be inspected and moves away from the conveyor means over a particular distance depending whether the package is properly sealed. When engaged by a properly sealed package the inspection means are moved a first distance, which causes an indicator or sensor to generate an “OK” or “GOOD” signal, which prevents the removal of the properly sealed package from the conveyor means.
However, when a leaky package, e.g. an improperly or inadequately sealed package contacts the inspection means, said means are moved a second distance, which is insufficient to cause the indicator or sensor to generate such a signal. Consequently, the package is classified as “FALSE” and removed from the conveyor means.
A major drawback of the apparatus as disclosed in U.S. Pat. No. 6,105,419 is that for a proper functioning the apparatus is only functional within a limited range of volumetric dimensions of the packages to be inspected, whereas the sealed packages to be inspected have to displace the inspection means a first distance in order to be classified as properly sealed packages. Any sealed package which does not displace the inspection means said first distance, fails to activate the indicator or sensor for generating a signal “GOOD”, said package is classified as improperly or inadequately sealed, whereas in fact the sealed package could be good and is therefore unnecessary rejected.
Hence the apparatus according to U.S. Pat. No. 6,105,419 is limited to a certain type of package, thus requiring modification of the apparatus when another type of package having different volumetric dimensions has to be inspected.
Moreover, the apparatus according to U.S. Pat. No. 6,105,419 only gives an indication “GOOD” or “FALSE”, and does not provide any accurate information concerning the actual volumetric dimensions of the individual sealed package.